Vapor generator

ABSTRACT

A vapor generator for supplying fuel in its vapor phase only to portable cooking, heating, lighting and other apparatus and devices which heretofore have utilized ignited liquid fuels in their operations. The generator comprises a combination liquid fuel and vapor containing housing, generally annular in form and elliptical in vertical cross section, from which the efflux is confined to fuel in its vapor phase only. Heating means applied to the generator maintain the liquid fuel at vaporizing temperatures, and ignitable contact between the liquid fuel and the heating means is prevented. The housing has a vapor outlet for conveying vapor for utilization in cooking or lighting means which are parts of the generator construction or for utilization in separate devices such as radiant heaters and the like.

United States Patent 1 Cross [11] 3,749,077 [451 Jul 31,1973

[ VAPOR GENERATOR 211 App]. No.: 192,028

Primary ExaminerWilliam F. ODea Assistant Examiner1-1arold JoyceAttorney-Bertha L. MacGregor 57 ABSTRACT A vapor generator for supplyingfuel in its vapor phase only to portable cooking, heating, lighting andother apparatus and devices which heretofore have utilized ignitedliquid fuels in their operations. The generator comprises a combinationliquid fuel and vapor containing housing, generally annular in form andelliptical in vertical cross section, from which the efi'lux is confinedto fuel in its vapor phase only. Heating means applied to the generatormaintain the liquid fuel at vaporizing temperatures, and ignitablecontact between the liquid fuel and the heating means is prevented. Thehousing has a vapor outlet for conveying vapor for utilization incooking or lighting means which are parts of the generator constructionor for utilization in separate devices such as radiant heaters and thelike.

PATENIED JUL3 1 ms 3, 749 i 077 Sam 1 or 4 21?? INVENTOR. JOHN E CRATTORNEY PATENIEBJum I973 $749,077

sum 2 0F 4 llllll 11122221122! ZF INVENTOR.

awn-5 JOHN F CROSS BY was ATTORNEY PATENlEoJuLa 1 I973 sum 3 0 4 1 III!INVENTOR. JOHN E CROSS ATTORNEY PATENIEDJUL31 ma SHEET 8 0F 3 ATTORNEY 1VAPOR GENERATOR This invention relates to a vapor generator forsupplying fuel in its vapor phase only to portable cooking, heating,lighting and power apparatus and devices which heretofore have utilizedignited liquid fuels in their operations.

The main object of this invention is to provide a vapor generatorcomprising a heated fuel container from which the efflux is confined tofuel in its vapor phase only. In some embodiments of the invention, thepassage of liquid fuel out of the generator housing to a burner which ispart of the embodiment is prevented by structural means in the containerwhich confine the liquid fuel but permit passage of vapor only to theburner; in other embodiments the liquid fuel container of the generatoralso confines the liquid but has a vapor outlet located in the top wallfor passage of vapor to other devices and apparatus which utilizeignitable vapor as their fuel.

Prior art devices utilizing ignited liquid fuels comprise a fuelcontainer wherein the fuel is discharged in liquid state by gravity,manual or heat pressurization, or by capillary action of a wick. Thesedevices are subject to operational limitations and require speciallyprepared fuels. The utilization of a fuel container as a vapor generatoraccording to my invention results in improved operation and adaptationof the construction to a wide range of readily available fuels. Commonfuels are available for internal combustion engines and are blends of areasonably wide temperature distillation range, containing additiveswhich improve performance for their intended applications. However, theuse of these fuels in devices as ignitable heat sources, involving flameignition under natural atmospheric conditions, is detrimental when suchcommon fuels leave the container as a liquid composite of variousdistillation fractions and containing additives intended for otherapplications. Related to which, the additives are concentrated in thecapillaries. ln pressurized devices, vaporization takes place in themetering value due to pressure reduction across the valve and theadditives are concentrated in valve and orifice parts, causingmalfunction.

In accordance with the invention herein disclosed, as applied toportable heating devices, the liquid fuel is distilled in the fuelcontainer and additives of the fuel remain in the residue liquid, whichcan be discarded.

When initiating operation, the lower temperature fractions of the fuelcomposites are first vaporized, permitting an earlier stablization ofoperation and flame characteristics than when the liquid fuel is meteredas a composite liquid in prior art devices. As the operation of thevapor generating unit continues, sufficiently higher vaporizationtemperatures are available to insure complete practical use of the fuel,thus extending adaptation to a wider range of fuels. During operation ofdevices utilizing the principle of the invention, the distillationprocess concentrates the additives and heavy end fractions as residueliquid which may be discarded before refilling the container.

Due to the lower density of vapor in respect to liquid fuel, thevolumetric consequence permits larger orifice metering, and that allowsmore precise control in small energy devices, as well as higheradaptability of orifices for metering liquid at gravity pressure,initially at cold start, with compatability of the same orificing for metering vapors under pressure head developed from heating.

Another benefit gained by application of the inventive principle toself-pressurizing heat devices is the minimizing of pressure build-up asa result of metering lower density vapors rather than the higher densityliquid fuel, causing a higher volume efflux minimizing the lowertemperature volatiles first during initial operation at lowertemperature and allowing the higher temperature volatiles to remain tobe volatilized under higher temperatures as operation continues,resulting in alleviating the pressure increment with temperature duringsustained operation.

Another object of the invention is to provide a combination fuelcontainer and vapor generating housing elliptical in cross section, inwhich all surfaces are curved as most ideal for strength of the housing,and, further, to enhance the passage of air in a smooth laminar flow toafford maximum amount of heat removal from the external surfaces of theinner peripheral wall of the vaporizing-liquid container, as well as toprovide a convergent-divergent passage for thermal syphon air to enhancethe maximum amount of air passing through the interior of the housing.The elliptical cross section design affords a maximum compromise betweenproximate and convection heat loss to minimize temperature build-up andsubsequent vapor pressure in the liquid container. The elliptical shapefurther provides a minimum exposure by geometry at its apex for radiantheat transfer from the flame capsule as it is deflected outward byheating utensils over the vaporizing fuel container when the inventionis embodied in a cooking stove.

In some embodiments of the invention, a small quantity of the liquidfuel in the vapor-producing container is utilized for heating thecontainer contents to thereby initiate the vaporization process. Forexample, in a selfcontained cooking stove in which the liquid fuelcontaining housing constitutes the body of the stove, a restrictedvolume of liquid fuel passes to an auxiliary chamber into communicationwith a metering valve which permits passage of the liquid fuel to aburner orifree in an air mixing chamber where it is ignited andfunctions to heat the fuel container to initiate the vapor producingprocess. After the estricted amount of liquid fuel in the auxiliarychamber has been consumed for the purpose stated, the supply cannot bereplenished while the vaporizing process continues. Thereafter, onlyfuel in the vapor phase can pass into the auxiliary chamber for passageto the cooking stove burner, where it functions to maintain vaporizingtemperatures in the container housing, as well as to heat the contentsof cooking utensils supported on the stove.

ln self-contained lighting apparatus, such as an incandescent mantleequipped lantern, the initiation of the vaporizing process is performedas it is in the cooking stove embodiment of the invention, by allowing asmall volume of liquid fuel to pass into an auxiliary chamber forpassage to a burner orifice, resulting in heating of the liquid fuel inthe container for converting the liquid fuel to vapor. Means areprovided for conducting unignited vapor to the lighting apparatus afterthe vaporiza tion process has been initiated, which requires a veryshort time, usually less than a minute.

In apparatus where the vapor is to be utilized for heating purposes,such as barbecue cookers, toasters, rotisseries and radiant heaters, inwhich the vapor generator is not a built-in part, the initial heating ofthe liquid fuel container of the generator may be performed by the useof a restricted amount of liquid fuel, in an auxiliary chamber, followedby conducting vapor out of the generator to the heating apparatus. Inthis embodiment of the invention, the liquid fuel burner has lowcapacity, i.e., only sufficient to maintain the heat required forvaporizing the liquid fuel in the generator. The heating means formaintaing the vaporizing temperature may be electrical, thus making itpossible to dispense with the use ofliquid fuel for initiating the vaporgenerating process.

The several embodiments referred to hereinabove as well as thegenerator, per se, are shown in the drawings.

In the drawings:

FIG. 1 is a vertical sectional view of a vapor generator embodying myinvention, adapted to convey vaporized fuel to other devices forcooking, roasting, radiant heating, and/or lighting.

FIG. 2 is a top view of the vapor generator embodied in a cooking stove.

FIG. 3 is a horizontal sectional view of the device shown in FIG. 2.

FIG. 4 is a vertical sectional view in the plane of the line 4-4 of FIG.3.

FIG. 5 is a fragmentary sectional view of a modification of thegenerator shown in FIGS. 2-4.

FIG. 6 is a longitudinal sectional view of the metering valve which ispart of the cooking stove and some other embodiments of the inventionshown herein.

FIG. 7 is an elevational side view ofa vapor operated barbecue,rotisserie and radiant heater designed to receive and ignite vaporizedfuel from the generator shown in FIG. 1.

FIG. 8 is a vertical sectional view of the vapor operated device of FIG.7, in the planes of the line 88 of FIG. 7.

FIG. 9 is a vertical sectional view ofa self generating vapor lanternembodying the invention.

FIG. 10 is a vertical sectional view of an electrically operated andcontrolled vapor generator adapted to convey vaporized fuel to otherdevices such as described herein.

FIGS. 1 and 4 show vertical sectional views of vapor generators whichembody similar housings each comprising a combination liquid fuel holderand vaporizing container, but differ in that the generator of FIG. 1 isdesigned to convey vaporized fuel to other devices whereas the generatorof FIGS. 2-4 is part ofa cooking stove in which the generated vapor isutilized for burning. The sectional view shown in FIG. 3 is applicablealso to the generator of FIG. 1 with respect to the construction of thesimilar housings which comprise the combination fuel container and fuelvaporizing means.

Referring to FIGS. 1 and 3, the generally annular housing whichfunctions as a fuel container and vapor generator is elliptical invertical section and preferably made of cast metal. The outer peripheralwall 21 of the housing is thickened in spaced apart areas as shown inFIG. 3 to facilitate the production processes and to provide a threadedfuel intake 22 closed by a threaded closure member 23. The innerperipheral wall 24 of the housing conforms generally to the shape of theouter peripheral 'wall 21 which is non-concentric with respect to theaxial center of the housing 20. The walls 21 and 24 enclose a chamber 25elliptical in vertical cross section, except as noted hereinafter, andcontinuous in horizontal cross section as shown in FIG. 3.

The elliptical vertical cross sectional shape of the chamber 25 isinterrupted by the metering rod 26 which extends in radial directionbeneath the chamber 25 just above the bottom of the housing 20 from themetering valve 27 shown diagrammatically in FIGS. 1, 3 and 4.

The internal contour of the elliptical chamber 25 also is altered in onesection, opposite the intake opening 22, by a vertical partition 28spaced from the peripheral inner wall 24 and connected thereto by sidepartition walls 29. The partition 28 is shorter than the height of thechamber 25, leaving a gap 30 between the upper edges of the partition28, 29, and the top of the chamber. The space between the partition 28,29, and the inner wall 24 provides an auxiliary chamber 31 communicatingwith the metering valve 27 through the passageway 32. Feet 33 supportthe housing 20 as a whole.

The generator of FIG. 1, designed to generate vapor to be utilized inother devices, is equipped with a burner 35 located in an air-vapormixing chamber 36 in the space between the peripheral inner walls 24 ofthe housing 20. The burner 35 receives vapor from the metering valve 27.The burner is restricted to capacity sufficient only to maintainvaporization of fuel in the chamber 25 to supply required vapor to theother devices. The vapor generated by the described apparatus (exceptthat consumed by the burner 35) passes from the chamber 25 through theconduit 37 to the device to be supplied with vapor for cooking,roasting, radiant heating or other uses.

The generator of FIGS. 2-5, embodied in a cooking stove, embodies thepreviously described parts 20-33 inclusive. The structural features ofthe combination cooking stove and vapor generator include a cup shapedair-vapor mixing member 40, with upper deflector plate 41, and burner 42in the mixing member in communication with the metering valve 27. Forcooking purposes, the housing 20 is provided on its upper surface withthree supports 43 which have a flat top surface 44 for supporting largecooking utensils (not shown) and a lower flat shoulder surface 45 forsmaller containers (not shown) which fit between the supports 44.

The modification shown in FIG. 5 differs from the FIGS. 1-4 constructionin the contour of the partition 28 and the shape of the housing walls21', 24 and chamber 31.

The operation of the vapor generators of FIGS. 1-5 is as follows: Theclosure member 23 is removed, the housing 20 is tilted to axiallyhorizontal position, with the intake opening 22 at the top, and fuel ispoured through the opening 22 into the chamber 25. Part of the fuelpasses through the gap 30 into the auxiliary chamber 31. Then thehousing is restored to its normal horizontal position in which the axisof the generator is vertical. The burner 35 (FIG. I) or 42 (FIG. 4) isignited. The fuel in the auxiliary chamber 31 is consumed by the burnerflame and cannot be replenished while the generator is in that operativeposition, but within a very short time, usually less than a minute, theheat produced by the flame heats the fuel in chamber 25 and generatespressure in the fuel chamber 25 resulting in generating of vapor whichpasses from the chamber 25. In the generator of FIG. 1, the vapor passesfrom the combination fuel container and vaporizer chamber 25 in twostreams; first, through the gap 30 to the auxiliary chamber 31 forpassage to the burner 35 which has restricted capacity for maintainingvaporization of fuel in chamber 25, and, secondly, through the conduit37 to a device such as a barbecue, rotisserie or radiant heater or othervapor operated appliance. In the generator of FIGS. 2-5, the vaporpasses from the combination fuel container and vaporizer chamber throughthe gap to the burner 42 for two purposes, namely, to provide heat tomaintain the vaporization of fuel in chamber 25, and also to heatcooking utensils supported on the surfaces 44 or 45 of supports 43.

The valve 27, shown diagrammatically in FIGS. 1, 3 and 4, is shown indetail in FIG. 6. It comprises a cylindrical housing 50,reduced-diameter threaded end 51, threaded outlet 52 communicating withthe burner of the generator of FIG. 1 or burner 42 of the cooking stoveof FIGS. 25, and open end 53 for mounting of the operating rod 26 of themetering valve. The rod 26 has an inner end 54 internally bored andthreaded to engage the threaded end of a conical valve stem 55 which isflattened at 56 for engagement by the pin 57, whereby rotation of thevalve stem is prevented while the operating rod 26 is rotated to adjustthe longitudinal position of the conical end of the stem 55 relativelyto the cylindrical housing end 51. The limiting of movement of theconical metering stem to non-rotative movement prevents wear of thestern.

FIGS. 7 and 8 illustrate a vapor operated barbecue, rotisserie andradiant heater 60 to which fuel vapor is conveyed from the vaporgenerator of FIG. 1 through the conduit 37. The apparatus 60 comprises aframe 61 provided with slots 62 for grill supports, wind screen 63,cover plate 64, porous refractory lining 65, porous light weightrefractory brick 66, distribution plate 67, distribution manifold 68 andhose 69 leading to the vapor generator conduit 37. The details of theheating apparatus of FIGS. 7 and 8 are immaterial; said apparatus beingshown merely to illustrate applications of the vapor generator toseparate devices.

FIG. 9 illustrates an application of the vapor generator to a lantern70. The generator resembles the one shown in FIGS. 2-5 built into acooking stove. The housing 20 and parts designated 21-33 have beendescribed heretofore. The lantern 70 comprises the aforesaid vaporgenerator and lantern parts such as the transparent side walls 71mounted in a groove formed in the top of the generator housing 20, topshield 72 circumferentially engaging the side walls 71, threaded bolt 73and nut 74, with ring 75, the bolt extending through the cover shield 72to tie the ring and nut to the lighting means within the lanternhousing. Said lighting means comprises an air-vapor mixing chambercasing 76 surrounding a burner 77 and extending upwardly to form acylindrical casing 78 for conducting vapor to lines 79 leading to a pairof incandescent mantles 80.

In this application of the invention, burning takes place at the vapororifice 77 to initiate sufficient heat to cause vaporization.Thereafter, vapors are admitted through the vapor orifice 77, mixed withair in the mixing chamber 78, and subsequent ignition takes place on thesurface of mantle 80, to cause incandescence. The radiant energy frommantles 80, in close proximity to the fuel container 21, maintainssufficient heating of the container to sustain vaporization of theliquid fuel.

FIG. 10 shows a modification of the generator of FIG. 1. The modifiedstructure is electrically operated and controlled. Since the burning ofliquid fuel at the initiation of the vaporizing process in thegenerators of the previously described constructions is not required inthe electrically operated and controlled mechanism of FIG. 10, theauxiliary chamber 31 and burner 35 have been eliminated in thismodification. The housing 20, comprising walls 21 and 24 which definethe elliptical chamber 25 for containing fuel and generating vaportherein, together with the vapor conveying conduit 37, are designated asheretofore described. The passage 32 is closed by a bolt 38.

In FIG. 10, the means for heating fuel in the chamber 25 to initiate andmaintain the vapor generating process is a Calrod type immersion heaterinserted into the chamber 25 at one side through an opening in thehousing wall 21. The outer end of the heater 90 extends through athreaded bearing 91 and nut 92, with wiring 93 leading to the controlbox 94. The wiring 95 conducts current from a l 10 volt electricalsupply. The control box contains a switch 96, switch operating lever 97,fixed on rod 98, strip thermostat 99, and thermostat adjustment cam 100.An off-on range selection knob 101 is mounted on the outer end of therod 98.

In all embodiments of the invention, the salient novel feature is thegenerating of vapor by unignited liquid fuel arid utilization of thevapor in apparatus or devices of which the generator is a part or inseparate devices or apparatus that receive the vapor from the generator.

I claim:

1. A vapor generator supplying fuel in its vapor phase only to cooking,heating, lighting and other apparatus comprising a. a liquid fuelcontaining housing in which the fuel is converted to vapor,

b. a burner maintaining the fuel in the housing at vaporizingtemperatures,

0. means preventing ignitable contact between the liquid fuel and theburner,

d. a vapor outlet in said housing conveying vapor to the burner, and

e. a vapor outlet at the top of said housing conveying vapor to separatevapor-utilization means,

said means preventing ignitable contact between the liquid fuel and theburner comprising a partition dividing the interior of the housing intoa main liquid fuel and vapor chamber and a smaller auxiliary chambercommunicating with each other by a restricted gap at the top of thepartition, said gap allowing a restricted volume of liquid fuel to passinto the auxiliary chamber when the housing is in horizontally axialposition and said partition preventing passage of liquid fuel when thehousing is in its operative horizontal position wherein the axis isvertical, whereby the restricted volume of liquid fuel can pass from theauxiliary chamber to the burner and serves when ignited to initiategenerating of vapor and when consumed cannot be replenished while thegenerator is in operative position, and only vapor can pass from thegenerator through the auxiliary chamber to the burner.

2. The vapor generator defined by claim 1 that supplies vapor tovapor-utilizing apparatus separate from the generator, and whichincludes a hose detachably connected to the vapor outlet at the top ofsaid housing and to said separate vapor-utilizing apparatus.

3. A vapor generator supplying fuel in its vapor phase only to cookingapparatus comprising a. a liquid fuel containing housing generallyannular in shape in which the fuel is vaporized,

b a burner located in a space between the inner peripheral walls of theannular housing maintaining the fuel at vaporizing temperatures andheating contents of cooking utensils,

c. means in the fuel containing housing preventing ignitable contactbetween the liquid fuel and the burner, and

d. a vapor conveying valved passageway between the housing and burner,

said means preventing ignitable contact between the liquid fuel and theburner comprising a partition dividing the interior of the housing intoa main liquid fuel and vapor chamber and a smaller auxiliary chambercommunicating with each other by a restricted gap at the top of thepartition, said gap allowing a restricted volume of liquid fuel to passinto the auxiliary chamber when the housing is in horizontally axialposition and said partition preventing passage of liquid fuel when thehousing is in its operative horizontal position wherein the axis isvertical, whereby the restricted volume of liquid fuel can pass from theauxiliary chamber to the burner and serves when ignited to initiategenerating of vapor and when consumed cannot be replenished while thegenerator is in operative position, and only vapor can pass from thegenerator through the auxiliary chamber to the burner.

4. The vapor generator defined by claim 3, in which the housing isprovided on its top surface with a plurality of cooking utensil supportshaving flat surfaces on two different levels supporting utensils ofdifferent diameters over the burner.

5. The vapor generator defined by claim 3, in which the housing iselliptical in cross section throughout the major part of its annularform.

6. The vapor generator defined by claim 3, which includes a meteringvalve located in the passageway between the housing and burner, saidmetering valve having a rotatable control rod actuating a non-rotatableconical valve stem in longitudinal directions.

7. A vapor generator supplying fuel in its vapor phase only to lightingapparatus embodying an incandescent mantel comprising a. a liquid fuelcontaining housing generally annular in shape in which fuel isvaporized,

b. a burner adjacent the housing for initiating vaporization of fuel inthe housing,

c. means in the fuel containing housing preventing ignitable contactbetween the fuel and the burner,

d. a vapor outlet in said housing and a passageway conveying vapor fromthe outlet to the burner,

e. lighting apparatus embodying an incandescent mantle mounted on thefuel containing housing, and

f. a mixing chamber and tubular conduit conveying vapor from the burnerorifice to the mantle in the lighting apparatus,

said means preventing ignitable contact between the liquid fuel and theburner comprising a partition dividing the interior of the housing intoa main liquid fuel and vapor chamber and a smaller auxiliary chambercommunicating with each other by a restricted gap at the top of thepartition, said gap allowing a restricted volume of liquid fuel to passinto the auxiliary chamber when the housing is in horizontally axialposition and said partition preventing passage of liquid fuel when thehousing is in its operative horizontal position wherein the axis isvertical, whereby the restricted volume of liquid fuel can pass from theauxiliary chamber to the burner and serves when ignited to initiategenerating of vapor and when consumed cannot be replenished while thegenerator is in operative position, and only vapor can pass from thegenerator through the auxiliary chamber to the burner.

1. A vapor generator supplying fuel in its vapor phase only to cooking,heating, lighting and other apparatus comprising a. a liquid fuelcontaining housing in which the fuel is converted to vapor, b. a burnermaintaining the fuel in the housing at vaporizing temperatures, c. meanspreventing ignitable contact between the liquid fuel and the burner, d.a vapor outlet in said housing conveying vapor to the burner, and e. avapor outlet at the top of said housing conveying vapor to separatevapor-utilization means, said means preventing ignitable contact betweenthe liquid fuel and the burner comprising a partition dividing theinterior of the housing into a main liquid fuel and vapor chamber and asmaller auxiliary chamber communicating with each other by a restrictedgap at the top of the partition, said gap allowing a restricted volumeof liquid fuel to pass into the auxiliary chamber when the housing is inhorizontally axial position and said partition preventing passage ofliquid fuel when the housing is in its operative horizontal positionwherein the axis is vertical, whereby the restricted volume of liquidfuel can pass from the auxiliary chamber to the burner and serves whenignited to initiate generating of vapor and when consumed cannot bereplenished while the generator is in operative position, and only vaporcan pass from the generator through the auxiliary chamber to the burner.2. The vapor generator defined by claim 1 that supplies vapor tovapor-utilizing apparatus separate from the generator, and whichincludes a hose detachably connected to the vapor outlet at the top ofsaid housing and to said separate vapor-utilizing apparatus.
 3. A vaporgenerator supplying fuel in its vapor phase only to cooking apparatuscomprising a. a liquid fuel containing housing generally annular inshape in which the fuel is vaporized, b. a burner located in a spacebetween the inner peripheral walls of the annular housing maintainingthe fuel at vaporizing temperatures and heating contents of cookingutensils, c. means in the fuel containing housing preventing ignitablecontact between the liquid fuel and the burner, and d. a vapor conveyingvalved passageway between the housing and burner, said means preventingignitable contact between the liquid fuel and the burner comprising apartition dividing the interior of the housing into a main liquid fueland vapor chamber and a smaller auxiliary chamber communicating witheach other by a restricted gap at the top of the partition, said gapallowing a restricted volume of liquid fuel to pass into the auxiliarychamber when the housing is in horizontally axial position and saidpartition preventing passage of liquid fuel when the housing is in itsoperative horizontal position wherein the axis is vertical, whereby therestricted volume of liquid fuel can pass from the auxiliary chamber tothe burner and serves when ignited to initiate generating of vapor andwhen consumed cannot be replenished while the generator is in operativeposition, and only vapor can pass from the generator through theauxiliary chamber to the burner.
 4. The vapor generator defined by claim3, in which the housing is provided on its top surface with a pluralityof cooking utensil supports having flat surfaces on two different levelssupporting utensils of different diameters over the burner.
 5. The vaporgenerator defined by claim 3, in which the housing is elliptical incross section throughout the major part of its annular form.
 6. Thevapor generator defined by claim 3, which includes a metering valvelocated in the passageway between the housing and burner, said meteringvalve having a rotatable control rod actuating a non-rotatable conicalvalve stem in lOngitudinal directions.
 7. A vapor generator supplyingfuel in its vapor phase only to lighting apparatus embodying anincandescent mantel comprising a. a liquid fuel containing housinggenerally annular in shape in which fuel is vaporized, b. a burneradjacent the housing for initiating vaporization of fuel in the housing,c. means in the fuel containing housing preventing ignitable contactbetween the fuel and the burner, d. a vapor outlet in said housing and apassageway conveying vapor from the outlet to the burner, e. lightingapparatus embodying an incandescent mantle mounted on the fuelcontaining housing, and f. a mixing chamber and tubular conduitconveying vapor from the burner orifice to the mantle in the lightingapparatus, said means preventing ignitable contact between the liquidfuel and the burner comprising a partition dividing the interior of thehousing into a main liquid fuel and vapor chamber and a smallerauxiliary chamber communicating with each other by a restricted gap atthe top of the partition, said gap allowing a restricted volume ofliquid fuel to pass into the auxiliary chamber when the housing is inhorizontally axial position and said partition preventing passage ofliquid fuel when the housing is in its operative horizontal positionwherein the axis is vertical, whereby the restricted volume of liquidfuel can pass from the auxiliary chamber to the burner and serves whenignited to initiate generating of vapor and when consumed cannot bereplenished while the generator is in operative position, and only vaporcan pass from the generator through the auxiliary chamber to the burner.